1. Field of the Invention
The invention relates to the field of draw-out circuit interrupters, and in particular concerns a draw-out circuit interrupter cradle configuration with a number of interlocks in a compact and durable arrangement.
2. Prior Art
Known cradles for draw-out circuit interrupters support the draw-out circuit interrupters in a compartment of a stationary enclosure, cabinet or the like in a manner permitting both removable mounting of the interrupter and back and forth movement of operative elements that engage or disengage electrical conductors that terminate in the enclosure. An example is disclosed in U.S. Pat. No. 4,315,115--Rexroad.
The interrupter includes a stationary frame and a conductor mechanism having a stationary contact and a movable contact that can be brought together to bridge across the fixed conductors that terminate at the enclosure, and lead back to bus bars on the supply and load sides of a power distribution network. The conductive jumper bar is likewise retractable, and the interrupter mechanism thus makes or breaks an electrical circuit including the permanent terminals and the bus bars. The cradle also facilitates the procedures of mounting and demounting the interrupter in the compartment, in a modular manner.
Known cradles comprise an interrupter-engaging frame movably coupled to an enclosure-engaging frame. The interrupter-receiving compartment of the stationary enclosure typically defines a rear wall provided with openings permitting the forward extension of stationary terminals, also known as stabs. The stabs are arranged in opposite sets which oppositely extend to a power-consuming load and power-supplying source respectively. The stabs define plug structures that engage in rearwardly facing receptacle terminals aligned for releasable interconnection with the stabs. The interrupter is thereby plugged into the interrupter-engaging frame, while the enclosure-engaging frame removably engages the enclosure.
Moving the interrupter-engaging frame relative to the enclosure-engaging frame correspondingly causes the interrupter to move between the open and closed positions. Thus the enclosure-engaging frame can remain stationary as the interrupter mechanism moves to achieve electrically connected or disconnected relationships between the stabs.
Known cradle configurations are not particularly apt for operatively supporting large interrupter devices. It would be advantageous to provide a more compact arrangement capable of operating larger interrupters without correspondingly multiplying the overall dimensions of the device. Additionally, it would be advantageous if the cradle mechanism itself included safety interlocks, that are undesirably absent from the cradle configurations known in the art. The present invention provides a number of interlocks in an interrupter cradle arrangement that is durable and compact.